The present invention relates to a gasoline engine and more particularly pertains to a small four-stroke gasoline engine with improvements on its lubricant passage ways and its mode of lubrication.
It is known that existing small four-stroke gasoline engines apply splashing lubrication in conjunction with pressure oil injection as its mode of lubrication, that is, to splash or make use of pressure to spread lubricants onto the surfaces of parts for lubrication. This mode is characterized in that it is required to dispose on the machine the structures of the lubricant pumps and splashing devices, which are relatively complicated. While the lubricating effects are general, there are dead angles and power consumption is large.